Dental casting machine



1949 'A. F. MISKUNAS 2,487,937

\ DENTAL CASTING MACHINE Filed June 1'7, 1946 2 Sheets-Sheet l INVENTOR ANTON -F'. MI SKUNAS BY ATTY.

Patented Nov. 15, 1949 UNITED STATES PATENT OFFICE DENTAL CASTING MACHINE Anton F. Miskunas, Chicago, Ill.

Application June 17, 1946, Serial No. 677,233

4 Claims.

.upon conditions and other operating factors.

In dental laboratories, there is need for various apparatus employing electric motors andit has been found highly desirable to combine dental casting machine instrumentalities with other apparatus such as polishing and grinding equipment for use with a common or single motor. This increases the flexibility of dental laboratory apparatus and materially, enhances, the use to which apparatus in a dental laboratory may be put. 7

Dental laboratories are usually small and constitute a comparatively small adjunct to the dental practitioners ofiice space. This renders it extremely advantageous to provide dual purpose equipment utilizing a single or common motor, such as centrifugal casting instrumentalities and polishin or grinding equipment. These respective instrumentalities have different load and operating characteristics so one should be conveniently and readily detachable from the other through the adjustment of the motor position so that either can be used with utmost efiiciency. This, together with other advantages, such as improved casting instrumentalities comprise the teachings of the present invention.

One object of the present invention is to simplify the construction and improve the operation of devices of the character mentioned.

Another object is to provide'an improved dental castin machine wherein dual crucibles are used in counter-balanced relation to each other.

Still another object is to provide an improved dental laboratory equipment embodying a power operating dental casting machine as an alternate of other power driven equipment operative with the same motor.

A further object is to provide an improved dental casting machine of centrifugal counter-balanced type embodying dual crucibles to accomplish that end.

A still further object is to provide an improved dental casting apparatus having a power driven -motor thatisoperatively connected or readily disconnected therewith. I Still a further object is to provide a dental d5 casting machine with a motor that is readily detachable or attachable therewith by adjusting the position thereof in relation to a coupling element. e

Other objects and advantages will appear from the following description of an illustrative embodiment of the present invention.

In the drawings:

Figure I is a front view in elevation of a device embodying features of the present invention.

Figure II is an end sectional view in elevation taken substantially along line 11-11 of Figure I.

Figure III is an end sectional view in elevation taken substantially along line III-III of Figure I.

Figure IV is a fragmentary perspective view of the gear housing and crucible support shaft showing the counter-balanced relation of the crucibles thereon.

Figure V is a plan sectional View taken substantially along line V-V of Figure I.

Figure VI is a fragmentary sectional view in elevation taken substantially along line VIVI of Figure V.

Figure VII is a the clutch taken fragmentary sectional view'of substantially along line VII-VII of Figure I.

Figure VIII is a plan view of the clutch face viewed substantially from line VIIIVIII of Figure VII.

The structure selected for illustration is not intended to serve as a limitation upon the scope or teachings of the invention, but is merely i1- lustrative thereof. There may be considerable variations and adaptations of all or part of the teachings depending upon the dictates of commercial practice. The present embodiment comprises a base [0 preferably though not essentially of rectangular configuration for mounting to the top surface of a work bench H or the like. The base I0 is provided with upstanding brackets l2l3, in this instance two, which are transversely disposed in parallel spaced relation to provide centrally alignedintegral ears I i-45.

The integral ears l4--l5 have axially aligned threaded bores ltll therethrough to receive a correspondingly threaded elongated rod l8 therethrough for threaded engagement therewith. The threaded rod 58 is journalled to confronting transverse sides i9-2fi comprising part of a motor casing mount 2i. Collars '2223 retain the threaded rod l8 against axial displacement relative to the motor casing mount 2i, but permit relative rotation therewith to linearly displace the motor casing mount 2| which is slidably supported on the transverse brackets through threaded stud fasteners elongated slots.636l provided in the confrontor grinding instrumentalities such as the wheel 28 are detachably fixed to an outwardly extending armature shaft 29 of the motor so that the latter will be useful for the usual grinding and polishing operations usually found necessary in a dental laboratory. These operations usually require high speeds for which motors 25 are usually designed, and for that reason no other load should be harnessed to the motor 25 during. such operations.

In order to provide an additional service for the motor 25, however, a dual service maybe provided by utilizing the motor shifting wheel 24 to cause oneconventional rubber damping clutch element 30 on the oppositely extending motor armature shaft end 3! to engage another complemental conventional rubber damping clutch element 32 fixed to a stud shaft 33 (Figure VII). The shaft 33 is journalled in an upstanding bearing bracket 34 bolted to the base it as at 35 (Figure II). The stud shaft 33 carries a spur gear 36 beyond the bearing bracket 34, and the gear 36 meshes with a pinion 37 fixed to a shaft 38 journalled between the bearing bracket 34 and another. upstanding confronting bracket 39. The latter is bolted as at 40 to the base it (Figures I and III).

The shaft 38 carries an appreciably larger spur gear 4| in a bell housing 42 having another pinion housing 43 thereon to comprise part of the bearing bracket 39. A pinion 44 is mounted on a driven stud shaft 45 journalled in a pinion housingshaft extension 46 superposed above a bell housing shaft extension 41 which supports the shaft 38. A spurgear 48 isfixed to the other end ofthe shaft '45 to mesh with the pinion 3'! to provide a double gear box involving the shafts 3845. This imparts a'more rugged construction and providesabetter balanced starting torque for the load on the driven shaft d5 that has an elongated extension 49 mounted in a tubular shaft housing 5|] comprising part of a face plate 5| formed integrally therewith. A bracket web 52 reinforces the tubular housing 59 relative to the bell housing face plate 5| (Figure IV) to rigidly support the shaft tube 51! with the elongated driven shaft 45 journalled therein.

The driven shaft 45 with its extension 49 terminates in a threaded extremity to receive a looking nut 53 to retain spacing collars 54-55 thereon for the reception of a rotary arm 58 which is slotted therethrough as at 57 to receive the shaft extension 49 therethrough. The spaced collars 54-55 frictionally engage both sides of the slotted arm 55 to retain its balanced or unbalanced position on the shaft extension :35 when the nut 53 is drawn tight. With this arrangement, the arm 56 may be positioned off-center to compensate for varying content loads carried in dental crucibles 596E.

The crucibles 55-436 are adjustably fixed iii-62 in ing arms 6556 of arcuate stirrup-type cradles 4 6l68, respectively. The cradles 6'i58 are apertured intermediate their arms 65-5B, respectively, to receive threaded stud terminals E8IG (Figure IV) therethrough to enable the mounting thereof to the extremities of the arm 55. The threaded stud terminals Bil-ill comprise, in this instance, integral longitudinal extensions of the dual crucible supporting rotary arm 56, and the cradles 5965 are retained thereon by fastener nuts I! and washers l2. With this arrangement, one crucible 59 could be used for cooling While the other crucible 60 is .centrifugally. casting responsive to the constant rotation of the supporting arm 55. A balanced orcounter-balanced rotary dual functioning apparatus isthus produced with uniform operating characteristics. 7

\ This dual crucible structural rotary support may also be utilized individually so that the crucibles 59-.5i',i may be alternatively utilized for centrifugal casting and, thereby, allow the other crucible to cool off whether empty or provided with .an investment and its content. An empty crucible would also .serve to effectively counterbalance, although the off-center adjustment of the rotary arm 55 could be utilized as an accurate balancing control depending upon the respective weightsin the crucibles, This coupledwith the double gear box. involving shafts 38.-li5,provides a sturdy, balanced, and highly, flexible casting machine that can be readily detached so that the motor 25 can be utilized to. operate the instrue mentalities 28 or the. latters counterpart,

While Ihave illustrated anddescribed a preferred embodiment of this invention, it must be understood that the invention is capable of considerable, variation. and modification without departing frointhe. spirit. of the invention, I, therefore, do not wish to be limited to the precise details of construction. set forth, but desire to avail myself of such variations and. modifications as come within the scope of the appended claims.

I claim:

.1. In a deviceof .the character described, the

combination with a base, of an electric motor on said base, a bearing bracket onsaid base, a driven shaft journalled in said bearing bracket, atrain of gears interposed between said driven shaft and said electric motor, an arm having aslotted-midportion, said arm being adjustably connected to said driven shaft within the limits of said slotted mid-portion to vary-the axial position of attachment along said arm, and dental casting crucibles fixed to the extremities of said arm for rotation responsive to the operation of said electric motor.

v2. In a device of the character described, the combination with a base, of an electric motor on said base, a bearing bracket on said base, a driven shaft journalled in said bearing bracket, a double train of gears interposedbetween said driven shaft and said electric motor, an arm having a slotted mid-portion, said arm being adjustably connected to said driven shaft Within the limits of said slotted mid-portion to vary the axial position of attachment along said arm, dental casting crucibles fixed to the extremities of said arm for rotation responsive to the operation of said electric motor, and means for shifting said electric motor on said base for operative connection and inoperative disconnection with said driven shaft.

3. In a device of the character described, the combination with a base, of an electric motor on said base, a bearing bracket on said base, a, driven shaft journalled in said bearing bracket, a train of gears interposed between said driven shaft and said electric motor, an arm having a slotted mid-portion, said arm being adjustably connected to said driven shaft within the limits of said slotted mid-portion to vary the axial position of attachment along said arm, dental casting crucibles fixed to the extremities of said arm for rotation responsive to the operation of said electric motor, coupler elements between said electric motor and said train of gears, and means for shifting said electric motor on said base for operative connection and inoperative disconnection of said coupler elements.

4. In a device of the character described, the combination with a base, of an electric motor on said base, a bearing bracket on said base, a driven shaft journalled in said bearing bracket, a train of gears interposed between said driven shaft and said electric motor, an arm having a slotted midportion, said arm being adjustably connected to said driven shaft within the limits of said slotted mid-portion to vary the axial position of attachment along said arm, dental casting crucibles fixed to the extremities of said arm for rotation responsive to the operation of said electric motor,

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,853,344 Fobert ---s-. Apr. 12, 1932 2,140,204 Griffin Dec. 13, 1938 2,222,266 Rubissow a Nov. 19, 1940 2,265,043 Moore Dec. 2, 1941 FOREIGN PATENTS Number Country Date Germany Dec. 3, 1929 

